Immune checkpoint inhibitors for POLE or POLD1 proofreading-deficient metastatic colorectal cancer.

BACKGROUND: POLE and POLD1 proofreading deficiency (POLE/D1pd) define a rare subtype of ultramutated metastatic colorectal cancer (mCRC; over 100 mut/Mb). Disease-specific data about the activity and efficacy of immune checkpoint inhibitors (ICIs) in POLE/D1pd mCRC are lacking and it is unknown whether outcomes may be different from mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) mCRCs treated with ICIs. PATIENTS AND METHODS: In this global study, we collected 27 patients with mCRC harboring POLE/D1 mutations leading to proofreading deficiency and treated with anti-programmed cell death-ligand 1 alone +/- anti-cytotoxic T-lymphocyte antigen-4 agents. We collected clinicopathological and genomic characteristics, response, and survival outcomes after ICIs of POLE/D1pd mCRC and compared them with a cohort of 610 dMMR/MSI-H mCRC patients treated with ICIs. Further genomic analyses were carried out in an independent cohort of 7241 CRCs to define POLE and POLD1pd molecular profiles and mutational signatures. RESULTS: POLE/D1pd was associated with younger age, male sex, fewer RAS/BRAF driver mutations, and predominance of right-sided colon cancers. Patients with POLE/D1pd mCRC showed a significantly higher overall response rate (ORR) compared to dMMR/MSI-H mCRC (89% versus 54%; P = 0.01). After a median follow-up of 24.9 months (interquartile range: 11.3-43.0 months), patients with POLE/D1pd showed a significantly superior progression-free survival (PFS) compared to dMMR/MSI-H mCRC [hazard ratio (HR) = 0.24, 95% confidence interval (CI) 0.08-0.74, P = 0.01] and superior overall survival (OS) (HR = 0.38, 95% CI 0.12-1.18, P = 0.09). In multivariable analyses including the type of DNA repair defect, POLE/D1pd was associated with significantly improved PFS (HR = 0.17, 95% CI 0.04-0.69, P = 0.013) and OS (HR = 0.24, 95% CI 0.06-0.98, P = 0.047). Molecular profiling showed that POLE/D1pd tumors have higher tumor mutational burden (TMB). Responses were observed in both subtypes and were associated with the intensity of POLE/D1pd signature. CONCLUSIONS: Patients with POLE/D1pd mCRC showed more favorable outcomes compared to dMMR/MSI-H mCRC to treatment with ICIs in terms of tumor response and survival.

Organ preservation after neoadjuvant long-course chemoradiotherapy versus short-course radiotherapy.

BACKGROUND: Potential differences in organ preservation between total neoadjuvant therapy (TNT) regimens integrating long-course chemoradiotherapy (LCCRT) and short-course radiotherapy (SCRT) in rectal cancer remain undefined. PATIENTS AND METHODS: This natural experiment arose from a policy change in response to the COVID-19 pandemic during which our institution switched from uniformly treating patients with LCCRT to mandating that all patients be treated with SCRT. Our study includes 323 locally advanced rectal adenocarcinoma patients treated with LCCRT-based or SCRT-based TNT from January 2018 to January 2021. Patients who achieved clinical complete response were offered organ preservation with watch-and-wait (WW) management. The primary outcome was 2-year organ preservation. Additional outcomes included local regrowth, distant recurrence, disease-free survival (DFS), and overall survival (OS). RESULTS: Patient and tumor characteristics were similar between LCCRT (n = 247) and SCRT (n = 76) cohorts. Median follow-up was 31 months. Similar clinical complete response rates were observed following LCCRT and SCRT (44.5% versus 43.4%). Two-year organ preservation was 40% [95% confidence interval (CI) 34% to 46%] and 31% (95% CI 22% to 44%) among all patients treated with LCCRT and SCRT, respectively. In patients managed with WW, LCCRT resulted in higher 2-year organ preservation (89% LCCRT, 95% CI 83% to 95% versus 70% SCRT, 95% CI 55% to 90%; P = 0.005) and lower 2-year local regrowth (19% LCCRT, 95% CI 11% to 26% versus 36% SCRT, 95% CI 16% to 52%; P = 0.072) compared with SCRT. The 2-year distant recurrence (10% versus 6%), DFS (90% versus 90%), and OS (99% versus 100%) were similar between WW patients treated with LCCRT and SCRT, respectively. CONCLUSIONS: While WW eligibility was similar between cohorts, WW patients treated with LCCRT had higher 2-year organ preservation and lower local regrowth than those treated with SCRT, yet similar DFS and OS. These data support induction LCCRT followed by consolidation chemotherapy as the preferred TNT regimen for patients with locally advanced rectal cancer pursuing organ preservation.

Different prognostic values of KRAS exon 2 submutations and BRAF V600E mutation in microsatellite stable (MSS) and unstable (MSI) stage III colon cancer: an ACCENT/IDEA pooled analysis of seven trials.

BACKGROUND: The prognostic value of KRAS and BRAFV600E mutations in stage III colon cancer (CC) remains controversial and has never been clearly analyzed in patients with microsatellite instability-high (MSI-H) tumors due to sample size limitations. Data are also lacking for KRAS submutations and prognosis. PATIENTS AND METHODS: We examined clinicopathological variables and prognosis in patients with surgically resected stage III CC who participated in seven clinical trials from the ACCENT/IDEA databases. Associations between KRAS exon 2 and BRAFV600E mutations and time to recurrence (TTR), overall survival (OS), and survival after recurrence (SAR) were assessed using a Cox model. We also analyzed the prognostic value of KRAS exon 2 submutations. RESULTS: Among 8460 patients, 11.4% had MSI-H status. In the MSI-H group, BRAFV600E, KRAS exon 2 mutants, and double-wild-type statuses were detected in 40.6%, 18.1%, and 41.3%, respectively, whereas and in the microsatellite stable (MSS) group, these were detected in 7.7%, 38.6%, and 53.8%, respectively. In the MSS group, 5-year TTR rates of 61.8%, 66.3%, and 72.9% were observed among patients with BRAFV600E, KRAS exon 2 mutants, and those who were DWT, respectively [adjusted hazard ratio (HR) = 1.58 and 1.31, both P < 0.001]. In the MSI-H group, 5-year TTR rates did not differ significantly among the mutated subgroups. Similar results were found for OS. However, survival after relapse was significantly shorter in the KRAS exon 2- and BRAFV600E-mutated patients in both MSS (adjusted HR = 2.06 and 1.15; both P < 0.05) and MSI-H (adjusted HR = 1.99 and 1.81; both P < 0.05) groups. In the MSS group, KRAS exon 2 mutations were associated with TTR, but only p.G12C, p.G12D, and p.G13D were associated with poor outcomes after disease recurrence. CONCLUSIONS: Testing for both KRAS and BRAFV600E mutations in stage III patients should be considered as they can better define individual patient prognosis, and may also enable patient selection for (neo)adjuvant trials dedicated to specific molecular subtypes with poor prognosis.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes.

AIM: Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes. METHOD: We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015. RESULTS: In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002). CONCLUSION: Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.

Clinical and molecular characterization of patients with cancer of unknown primary in the modern era.

BACKGROUND: On the basis of historical data, patients with cancer of unknown primary (CUP) are generally assumed to have a dismal prognosis with overall survival of less than 1 year. Treatment is typically cytotoxic chemotherapy guided by histologic features and the pattern of metastatic spread. The purpose of this study was to provide a clinical and pathologic description of patients with CUP in the modern era, to define the frequency of clinically actionable molecular alterations in this population, to determine how molecular testing can alter therapeutic decisions, and to investigate novel uses of next-generation sequencing in the evaluation and treatment of patients with CUP. PATIENTS AND METHODS: Under Institutional Review Board approval, we identified all CUP patients evaluated at our institution over a recent 2-year period. We documented demographic information, clinical outcomes, pathologic evaluations, next-generation sequencing of available tumor tissue, use of targeted therapies, and clinical trial enrollment. RESULTS: We identified 333 patients with a diagnosis of CUP evaluated at our institution from 1 January 2014 through 30 June 2016. Of these patients, 150 had targeted next-generation sequencing carried out on available tissue. Median overall survival in this cohort was 13 months. Forty-five of 150 (30%) patients had potentially targetable genomic alterations identified by tumor molecular profiling, and 15 of 150 (10%) received targeted therapies. Dominant mutation signatures were identified in 21 of 150 (14%), largely implicating exogenous mutagen exposures such as ultraviolet radiation and tobacco. CONCLUSIONS: Patients with CUP represent a heterogeneous population, harboring a variety of potentially targetable alterations. Next-generation sequencing may provide an opportunity for CUP patients to benefit from novel personalized therapies.

Predicted vitamin D status and colon cancer recurrence and mortality in CALGB 89803 (Alliance).

BACKGROUND: Observational studies suggest that higher levels of 25-hydroxyvitamin D3 (25(OH)D) are associated with a reduced risk of colorectal cancer and improved survival of colorectal cancer patients. However, the influence of vitamin D status on cancer recurrence and survival of patients with stage III colon cancer is unknown. PATIENTS AND METHODS: We prospectively examined the influence of post-diagnosis predicted plasma 25(OH)D on outcome among 1016 patients with stage III colon cancer who were enrolled in a National Cancer Institute-sponsored adjuvant therapy trial (CALGB 89803). Predicted 25(OH)D scores were computed using validated regression models. We examined the influence of predicted 25(OH)D scores on cancer recurrence and mortality (disease-free survival; DFS) using Cox proportional hazards. RESULTS: Patients in the highest quintile of predicted 25(OH)D score had an adjusted hazard ratio (HR) for colon cancer recurrence or mortality (DFS) of 0.62 (95% confidence interval [CI], 0.44-0.86), compared with those in the lowest quintile (Ptrend = 0.005). Higher predicted 25(OH)D score was also associated with a significant improvement in recurrence-free survival and overall survival (Ptrend = 0.01 and 0.0004, respectively). The benefit associated with higher predicted 25(OH)D score appeared consistent across predictors of cancer outcome and strata of molecular tumor characteristics, including microsatellite instability and KRAS, BRAF, PIK3CA, and TP53 mutation status. CONCLUSION: Higher predicted 25(OH)D levels after a diagnosis of stage III colon cancer may be associated with decreased recurrence and improved survival. Clinical trials assessing the benefit of vitamin D supplementation in the adjuvant setting are warranted. CLINICALTRIALS.GOV IDENTIFIER: NCT00003835.

Survival following early-stage colon cancer: an ACCENT-based comparison of patients versus a matched international general population†.

BACKGROUND: Post-treatment survival experience of early colon cancer (CC) patients is well described in the literature, which states that cure is probable for some patients. However, comparisons of treated patients' survival versus that expected from a matched general population (MGP) are limited. PATIENTS AND METHODS: A total of 32 745 patients from 25 randomized adjuvant trials conducted from 1977 to 2012 in 41 countries were pooled. Observed long-term survival of these patients was compared with expected survival matched on sex, age, country, and year, both overall and by stage (II and III), sex, treatment [surgery, 5-fluorouracil (5-FU), 5-FU + oxaliplatin], age (<70 and 70+), enrollment year (pre/post 2000), and recurrence (yes/no). Comparisons were made at randomization and repeated conditional on survival to 1, 2, 3, and 5 years. CC and MGP equivalence was tested, and observed Kaplan-Meier survival rates compared with expected MGP rates 3 years out from each landmark. Analyses were also repeated in patients without recurrence. RESULTS: Within most cohorts, long-term survival of CC patients remained statistically worse than the MGP, though conditional survival generally improved over time. Among those surviving 5 years, stage II, oxaliplatin-treated, elderly, and recurrence-free patients achieved subsequent 3-year survival rates within 5% of the MGP, with recurrence-free patients achieving equivalence. CONCLUSIONS: Conditional on survival to 5 years, long-term survival of most CC patients on clinical trials remains modestly poorer than an MGP, but achieves MGP levels in some subgroups. These findings emphasize the need for access to quality care and improved treatment and follow-up strategies.

A phase II study of gemcitabine and cisplatin plus sorafenib in patients with advanced biliary adenocarcinomas.

BACKGROUND: This study evaluated the addition of sorafenib to gemcitabine and cisplatin in biliary adenocarcinoma first-line therapy. METHODS: Patients with advanced biliary adenocarcinomas received gemcitabine 1000 mg m(-2) and cisplatin 25 mg m(-2) on a 2 weeks on/1 week off cycle and sorafenib 400 mg twice daily. After the initial 16 patients were enrolled, the chemotherapy doses were amended in view of grade 3 and 4 hand-foot skin reaction and haematologic toxicity. Subsequently, 21 patients received gemcitabine 800 mg m(-2), cisplatin 20 mg m(-2) and sorafenib 400 mg. The primary end point was an improvement in 6-month progression-free survival (PFS6) from historical 57-77% (90% power, type I error of 10%). Pretreatment pERK, evaluated by immunostaining, was correlated with clinical outcome. RESULTS: A total of 39 patients were accrued. The most common grade 3-4 toxicities noted in >10% of patients were fatigue, elevated liver function tests and haematologic toxicities including thromboemboli, hyponatraemia and hypophosphataemia. Six-month progression-free survival was 51% (95% confidence interval (CI) 34-66%). Median PFS and overall survival were 6.5 (95% CI: 3.5-8.3) and 14.4 months (95% CI: 11.6-19.2 months), respectively. No correlation was observed between pERK and outcomes. CONCLUSION: The addition of sorafenib to gemcitabine and cisplatin in biliary adenocarcinomas did not improve efficacy over historical data, and toxicity was increased.

Dynamic contrast enhanced-MRI for the detection of pathological complete response to neoadjuvant chemotherapy for locally advanced rectal cancer.

OBJECTIVE: To determine the ability of dynamic contrast enhanced (DCE-MRI) to predict pathological complete response (pCR) after preoperative chemotherapy for rectal cancer. METHODS: In a prospective clinical trial, 23/34 enrolled patients underwent pre- and post-treatment DCE-MRI performed at 1.5T. Gadolinium 0.1 mmol/kg was injected at a rate of 2 mL/s. Using a two-compartmental model of vascular space and extravascular extracellular space, K(trans), k(ep), v(e), AUC90, and AUC180 were calculated. Surgical specimens were the gold standard. Baseline, post-treatment and changes in these quantities were compared with clinico-pathological outcomes. For quantitative variable comparison, Spearman's Rank correlation was used. For categorical variable comparison, the Kruskal-Wallis test was used. P ≤ 0.05 was considered significant. RESULTS: Percentage of histological tumour response ranged from 10 to 100%. Six patients showed pCR. Post chemotherapy K(trans) (mean 0.5 min(-1) vs. 0.2 min(-1), P = 0.04) differed significantly between non-pCR and pCR outcomes, respectively and also correlated with percent tumour response and pathological size. Post-treatment residual abnormal soft tissue noted in some cases of pCR prevented an MR impression of complete response based on morphology alone. CONCLUSION: After neoadjuvant chemotherapy in rectal cancer, MR perfusional characteristics have been identified that can aid in the distinction between incomplete response and pCR. KEY POINTS: Dynamic contrast enhanced (DCE) MRI provides perfusion characteristics of tumours. These objective quantitative measures may be more helpful than subjective imaging alone Some parameters differed markedly between completely responding and incompletely responding rectal cancers. Thus DCE-MRI can potentially offer treatment-altering imaging biomarkers.

XELOX vs FOLFOX-4 as first-line therapy for metastatic colorectal cancer: NO16966 updated results.

BACKGROUND: We report updated overall survival (OS) data from study NO16966, which compared capecitabine plus oxaliplatin (XELOX) vs 5-fluorouracil/folinic acid plus oxaliplatin (FOLFOX4) as first-line therapy in metastatic colorectal cancer. METHODS: NO16966 was a randomised, two-arm, non-inferiority, phase III comparison of XELOX vs FOLFOX4, which was subsequently amended to a 2 × 2 factorial design with further randomisation to bevacizumab or placebo. A planned follow-up exploratory analysis of OS was performed. RESULTS: The intent-to-treat (ITT) population comprised 2034 patients (two-arm portion, n=634; 2 × 2 factorial portion, n=1400). For the whole NO16966 study population, median OS was 19.8 months in the pooled XELOX/XELOX-placebo/XELOX-bevacizumab arms vs 19.5 months in the pooled FOLFOX4/FOLFOX4-placebo/FOLFOX4-bevacizumab arms (hazard ratio 0.95 (97.5% CI 0.85-1.06)). In the pooled XELOX/XELOX-placebo arms, median OS was 19.0 vs 18.9 months in the pooled FOLFOX4/FOLFOX4-placebo arms (hazard ratio 0.95 (97.5% CI 0.83-1.09)). FOLFOX4 was associated with more grade 3/4 neutropenia/granulocytopenia and febrile neutropenia than XELOX, and XELOX with more grade 3 diarrhoea and grade 3 hand-foot syndrome than FOLFOX4. CONCLUSION: Updated survival data from study NO16966 show that XELOX is similar to FOLFOX4, confirming the primary analysis of progression-free survival. XELOX can be considered as a routine first-line treatment option for patients with metastatic colorectal cancer.

Efficacy of capecitabine versus 5-fluorouracil in colorectal and gastric cancers: a meta-analysis of individual data from 6171 patients.

BACKGROUND: To compare the effects of oral capecitabine-containing chemotherapy regimens with i.v. 5-fluorouracil (5-FU)-containing chemotherapy regimens on overall survival in patients with gastrointestinal cancers. METHODS: A meta-analysis, based on individual patient data from six randomised non-inferiority trials, was carried out at the request of regulatory authorities to compare the effects of single-agent capecitabine or capecitabine-containing chemotherapy versus matched 5-FU-based regimens in terms of overall survival in patients with stage III colon, metastatic colorectal or advanced gastric cancer. RESULTS: Data from a total of 6171 patients with stage III colon cancer (n = 1987), metastatic colorectal cancer (n = 3868) or advanced gastric cancer (n = 316) were included. A total of 3097 patients were treated with capecitabine-containing chemotherapy and 3074 patients with 5-FU-containing chemotherapy. The unadjusted hazard ratio for overall survival for capecitabine-containing chemotherapy versus 5-FU-containing chemotherapy was 0.94 (95% confidence interval 0.89-1.00; P = 0.0489). CONCLUSIONS: Oral capecitabine is at least equivalent to i.v. 5-FU in terms of overall survival in patients with gastrointestinal cancers. Capecitabine and 5-FU can be used interchangeably in these patient populations.

Surgery with curative-intent in patients treated with first-line chemotherapy plus bevacizumab for metastatic colorectal cancer First BEAT and the randomised phase-III NO16966 trial.

BACKGROUND: Complete resection of metastases can result in cure for selected patients with metastatic colorectal cancer. METHODS: First BEAT evaluated the safety of bevacizumab with first-line chemotherapy in 1914 patients. Prospectively collected data from 225 patients who underwent curative-intent surgery were analysed, including an exploratory comparison of resection rate in patients treated with different regimens. NO16966 compared efficacy of oxaliplatin-based chemotherapy plus bevacizumab or placebo in 1400 patients. A retrospective analysis of resection rate was undertaken. RESULTS: In First BEAT, 225 out of 1914 patients (11.8%) underwent curative-intent surgery at median 64 days (range 42-100) after the last dose of bevacizumab. R0 resection was achieved in 173 out of 225 patients (76.9%). There were no surgery-related deaths and serious post-operative complications were uncommon, with grade 3/4 bleeding and wound-healing events reported in 0.4% and 1.8%, respectively. Resection rates were highest in patients receiving oxaliplatin-based combination chemotherapy (P=0.002), possibly confounded by patient selection. In NO16966, 44 out of 699 patients treated with bevacizumab (6.3%) and 34 out of 701 patients treated with placebo (4.9%) underwent R0 metastasectomy (P=0.24). CONCLUSIONS: The rate of serious post-operative complications in First BEAT was comparable to historical controls without bevacizumab. In NO16966, there were no statistically significant differences in resection rates or overall survival in patients treated with bevacizumab vs placebo.

A phase I study of erlotinib in combination with gemcitabine and radiation in locally advanced, non-operable pancreatic adenocarcinoma.

PURPOSE: To determine the maximum tolerated dose (MTD) of erlotinib when administered concurrently with twice weekly gemcitabine and radiation therapy (RT) for locally advanced pancreatic cancer, assess the safety and toxicity profile of this combination and secondarily evaluate response, time to tumor progression and overall survival. METHODS: Patients with untreated locally advanced pancreas cancer were treated with daily erlotinib in combination with gemcitabine 40 mg/m(2)/30 min twice weekly and RT delivered at 180 cGy/day in 28 fractions over 5.5 weeks for a total of 5040 cGy. Erlotinib was dose escalated in successive cohorts (100 mg, 125 mg). When the MTD was determined, the cohort was expanded to better define toxicity and preliminarily efficacy. All patients were surgically staged. After chemoradiation, patients received maintenance weekly gemcitabine 1000 mg/m(2) on days 1 and 8 of a 21 day cycle and daily erlotinib for four cycles. RESULTS: Three patients were treated at dose level 1 (erlotinib 100 mg) without limiting toxicity. Two of six patients at dose level 2 (erlotinib 125 mg) had dose-limiting toxicities, neutropenia and thrombocytopenia, causing dose delay and elevated liver enzymes. The MTD for erlotinib in combination with twice weekly gemcitabine-based chemoradiation was 100 mg/day. Eleven additional patients were treated at dose level 1. All twenty patients were assessable for toxicity. Seventeen patients were assessable for response. The partial response rate was 35% and 53% had stable disease. The median survival for all patients was 18.7 months. CONCLUSION: In combination with fixed dose gemcitabine at 40 mg/m(2) twice weekly and radiation at 180 cGy/day, the MTD of erlotinib was found to be 100 mg/day. This is a relatively well tolerated, biologically active combination in a poor prognostic cancer.

MethyLight: a high-throughput assay to measure DNA methylation.

Cytosine-5 DNA methylation occurs in the context of CpG dinucleotides in vertebrates. Aberrant methylation of CpG islands in human tumors has been shown to cause transcriptional silencing of tumor-suppressor genes. Most methods used to analyze cytosine-5 methylation patterns require cumbersome manual techniques that employ gel electrophoresis, restriction enzyme digestion, radiolabeled dNTPs or hybridization probes. The development of high-throughput technology for the analysis of DNA methylation would significantly expand our ability to derive molecular information from clinical specimens. This study describes a high-throughput quantitative methylation assay that utilizes fluorescence-based real-time PCR (TaqMan) technology that requires no further manipulations after the PCR step. MethyLight is a highly sensitive assay, capable of detecting methylated alleles in the presence of a 10,000-fold excess of unmethylated alleles. The assay is also highly quantitative and can very accurately determine the relative prevalence of a particular pattern of DNA methylation. We show that MethyLight can distinguish between mono-allelic and bi-allelic methylation of the MLH1 mismatch repair gene in human colorectal tumor specimens. The development of this technique should considerably enhance our ability to rapidly and accurately generate epigenetic profiles of tumor samples.

Phase I clinical and pharmacology study of topotecan given daily for 5 consecutive days to patients with advanced solid tumors, with attempt at dose intensification using recombinant granulocyte colony-stimulating factor.

BACKGROUND: Topotecan has been shown in previous studies to be a specific inhibitor of topoisomerase I, a nuclear enzyme required for DNA replication and transcription. PURPOSE: Our objectives in this phase I clinical trial were to determine the maximum tolerated dose, dose-limiting toxic effects, and recommended phase II dose of topotecan and to define the pharmacokinetics of topotecan in humans. METHODS: Forty-three patients with advanced, incurable solid tumors were treated. Doses ranged from 0.5 to 2.0 mg/m2 daily for five days [corrected], with treatment cycles repeated initially every 28 days. Following the identification of the standard maximum tolerated dose, further dose escalations were attempted by following topotecan cycles with recombinant granulocyte colony-stimulating factor (rG-CSF). RESULTS: The maximum tolerated dose without rG-CSF for patients without prior cytotoxic therapy was 1.75 mg/m2 daily. The maximum tolerated dose for previously treated patients was 1.50 mg/m2 daily. The dose-limiting toxic effect was myelosuppression, with granulocytopenia being most commonly observed. Use of rG-CSF did not permit topotecan dose intensification, since thrombocytopenia and fatigue rapidly emerged as dose-limiting toxic effects. Plasma half-lives of topotecan (lactone form) were approximately 10 and 100 minutes for distribution and elimination phases, respectively. CONCLUSIONS: The doses of topotecan recommended for use in phase II clinical trials in solid tumors are 1.5 and 1.25 mg/m2 daily in previously untreated and previously treated patients, respectively. Based on observed rates of recovery from myelosuppression, treatment should be possible on a 21-day cycle. Dose intensification was not possible with the use of rG-CSF; however, rG-CSF may be a useful addition to the regimens of those few patients who experience either prolonged granulocytopenia or neutropenic sepsis or those who are not able to receive their second treatment cycle by day 21.

CpG island hypermethylation in human colorectal tumors is not associated with DNA methyltransferase overexpression.

The molecular basis of aberrant hypermethylation of CpG islands observed in a subset of human colorectal tumors is unknown. One potential mechanism is the up-regulation of DNA (cytosine-5)-methyltransferases. Recently, two new mammalian DNA methyltransferase genes have been identified, which are referred to as DNMT3A and DNMT3B. The encoded proteins differ from the predominant mammalian DNA methyltransferase DNMT1 in that they have a substantially higher ratio of de novo to maintenance methyltransferase activity. We have used a highly quantitative 5' nuclease fluorogenic reverse transcription-PCR method (TaqMan) to analyze the expression of all three DNA methyltransferase genes in 25 individual colorectal adenocarcinoma specimens and matched normal mucosa samples. In addition, we examined the methylation patterns of four CpG islands [APC, ESR1 (estrogen receptor), CDKN2A (p16), and MLH1] to determine whether individual tumors show a positive correlation between the level of DNA methyltransferase expression and the frequency of CpG island hypermethylation. All three methyltransferases appear to be up-regulated in tumors when RNA levels are normalized using either ACTB (beta-actin) or POLR2A (RNA pol II large subunit), but not when RNA levels are normalized with proliferation-associated genes, such as H4F2 (histone H4) or PCNA. The frequency or extent of CpG island hypermethylation in individual tumors did not correlate with the expression of any of the three DNA methyltransferases. Our results suggest that deregulation of DNA methyltransferase gene expression does not play a role in establishing tumor-specific abnormal DNA methylation patterns in human colorectal cancer.

Influence of inflammatory bowel disease on the ability of patients to tolerate systemic fluorouracil-based chemotherapy.

PURPOSE: To evaluate the safety of administering fluorouracil (5FU)-based chemotherapy to cancer patients with inflammatory bowel disease (IBD). PATIENTS AND METHODS: We retrospectively reviewed all patients entered into the Memorial Sloan-Kettering Cancer Center clinical data base from 1985 through 1995 who had a diagnosis of IBD, had a gastrointestinal malignancy, and were treated with systemic 5FU-based chemotherapy. A total of 19 patient charts were identified and reviewed. RESULTS: Fifty-three percent of patients reviewed experienced severe (grade III/IV) diarrhea on treatment. Sixty percent of patients with a history of active IBD and 40% of patients with a history of inactive IBD experienced severe diarrhea on treatment. The incidence of severe diarrhea did not appear to be substantially influenced by age, schedule of 5FU administration, concurrent radiation, or type of IBD. CONCLUSION: While there does appear to be an increased risk of diarrhea exacerbation in IBD patients treated with 5FU, a substantial number of patients tolerate chemotherapy without increased difficulty. The degree of IBD activity or other clinical parameters can not be used to predict accurately the likelihood of toxicity.

Interferon alfa-2a and fluorouracil in the treatment of patients with advanced esophageal cancer.

PURPOSE: The trial was undertaken to determine the response rate to and toxicities from the combination of interferon alfa-2a (IFN) and fluorouracil (FU) in patients with advanced esophageal cancer. MATERIALS AND METHODS: In this prospective phase II trial conducted at a large tertiary referral cancer center and university hospital, 40 patients with advanced locoregional, metastatic epidermoid, or adenocarcinoma of the esophagus were given FU 750 mg/m2 by 24-hour continuous intravenous infusion days 1 to 5, followed by weekly outpatient bolus FU 750 mg/m2 and IFN 9 x 10(6) U three times per week from day 1. Dose was attenuated for fatigue, neurotoxicity, gastrointestinal toxicity, and myelosuppression. RESULTS: Complete and partial responses were seen in 10 of 37 assessable patients with esophageal cancer (27%; 95% confidence interval, 0.13 to 0.41). Although substantial, toxicity was tolerable and primarily involved fatigue and mild myelosuppression. The median duration of response was 6.4 months (range, 2.8 to 14+ months). CONCLUSION: The combination of IFN and FU is an active regimen in the treatment of advanced esophageal cancer with a response rate similar to that reported for cisplatin-containing combinations in similar patient populations. Further studies based on this combination are indicated.

A phase II trial of pleurectomy/decortication followed by intrapleural and systemic chemotherapy for malignant pleural mesothelioma.

PURPOSE: This study investigated the feasibility of a novel approach to the treatment of malignant pleural mesothelioma by combining surgical resection with immediate postoperative intrapleural chemotherapy and subsequent systemic chemotherapy. PATIENTS AND METHODS: Patients with biopsy-proven, resectable malignant pleural mesothelioma underwent pleurectomy/decortication immediately followed by intrapleural chemotherapy with cisplatin 100 mg/m2 and mitomycin 8 mg/m2. Systemic chemotherapy was started 3 to 5 weeks postoperatively and included cisplatin 50 mg/m2 on days 1, 8, 15, 22, 36, 43, 50, and 57, and mitomycin 8 mg/m2 on days 1 and 36. Patients were then monitored by serial chest and abdominal computed tomographic (CT) scans every 3 months until death or for a minimum of 18 months, whichever occurred first. RESULTS: Of 36 patients entered onto the study, 28 had pleurectomy/decortication and intrapleural chemotherapy. There was one postoperative death, and two episodes of grade 4 renal toxicity after intrapleural chemotherapy. The 23 patients who also had systemic chemotherapy received a median of 80% and 87% of the planned total cisplatin and mitomycin doses, respectively. No grade 3 or 4 toxicities were observed. The overall survival rate of the 27 patients who were originally candidates for systemic chemotherapy was 68% at 1 year and 40% at 2 years, with a median survival duration of 17 months. Locoregional disease was the most common form of relapse (16 of 20 patients). CONCLUSION: This short but aggressive combined modality regimen was generally well tolerated, but should not be used outside of a protocol setting because of the potential for serious toxicity. Overall survival was as good or better than with previously reported multimodality approaches, but other strategies are needed to improve local control.